This is where you create your own backend for the server, not just use an existing service like Parse. This will probably be your only introduction to server side coding in this class and is meant only to give you a feel for it, not make you experts at it.

Self explanatory

Google "download nodejs" and download nodejs. Nodejs is basically javascript packaged for servers (not a browser) and will enable us to create a simple server. During the installation instructions make sure you select the option to install nodejs to the path (which should be the default).

In your terminal, first make sure you have access to node by typing "node --version". If that command returns something succesfully, then Nodejs is installed. Once you've verified nodejs is installed on the terminal, then do the following at the root of your repository:

npm install -g nodemon
npm install

NOTE: If on a mac, you'll probably need to prefix the above command with "sudo", so it would look more like this:

sudo npm install -g nodemon
sudo npm install

You need to tell Nodejs what file it should use to start a server. Open a terminal in this repo's root directory and type:

nodemon server.js

A server is now listening for requests. Also notice that if you modify server.js, the server will restart. This is because we are using "nodemon", which is a tool for development that automatically restarts the server when you write new code.

You need to point your parseService at your new server (instead of Parse where it pointed to yesterday). Your server is located at localhost:3000, which means the GET endpoint will be located at http://localhost:3000/get and the POST endpoint will be located at http://localhost:3000/post

In server.js there is a variable called inMemoryDB which contains the chat logs. Modify the code to return all the messages. Remember also that on your browser you were expecting all the messages to be contained within a "results" property on the response.data object. As a general rule you always need to make sure your server and your browser play nice. Remember that console.log is your best friend, on both the browser and the server. You can only debug problems if you know what is happening as the code executes.

Now you need to make sure the POST endpoint actually does something. Add new chat messages to the end of the messages array of the inMemoryDb, probably using something like inMemoryDb.data.messages.push(newChatMessageObj);

Make sure a new message has a createdAt property telling you when it was created. You can get a number representing the current time by invoking the function "Date.now()" Also make sure each new post has random string for its objectId. This isn't important now but is best practice in a database of any type.

Once you get this working, you may notice that new entries are being put at the bottom of the screen, not the top. This is because we are pushing to the end of the array. To fix this, you will need to reverse the $scope.messages in MainCtrl.js by calling $scope.messages.reverse().

Now delete the variable inMemoryDB. We're going to make the data be persistent so that whenver you POST new chat messages, they get saved to disk. Towards this end, at the top of server.js, you'll notice there's an unused variable called persistentDb.

The persistentDatabase is a little harder to work with than the in memory database but will actually save your information to the hard drive after you post data. We need to change our POST and GET handler functions to use this persistent database.

You interact with the persistent database a lot like the in memory database but the difference is that instead of using dots to get deeper into the datbase you use slashes. So if you accessed the chat messages in the in memory database with

inMemoryDb.data.messages

you would get it with the persistent database using

persistentDb.getData('/data/messages')

Similarly, if wrote to the in memory db with

inMemoryDb.data.messages.push(newChatMessageObj)

you would accomplish the same thing with the persistent db by writing

persistentDb.pushToArray('/data/messages', newChatMessageObj)

If you want a better understanding of the persistent database, you can browse the documentation here: https://www.npmjs.com/package/node-json-db

Don't get worried if you find this part frustrating. Part of what we want you to learn is how to learn new libraries and databases since technology is always changing.

I don't expect all of you to get this far, but if you do it's time to up your game by actually pushing to a server in the cloud. First, in a separate repo follow the tutorial specified here: https://devcenter.heroku.com/articles/getting-started-with-nodejs#introduction By following this tutorial in an isolated environment, you will get a better feel for how heroku works. Then once you feel like you understand it well enough, repeat those same steps with this chat repo, primarily the "heroku create" step and the "git push heroku master" step.

We need to make the browser point to your newly deploy server, so update the $http endpoints from their local locations like http://localhost:3000 to the url Heroku told you about after deploying. This will usually be something like https://thawing-ravine-9764.herokuapp.com or similarly named location.

Once you have it working, have your friends point to the same location and magically now, all of you will be looking at the same chat log!

Congratulations, you've created your own simple re-creation of the Parse Service!